Independents: Who and How Many?

By Jon Cohen
Washington Post Staff Writer
Saturday, June 30, 2007; 6:02 PM

This poll focuses on those who say they are "an independent" when asked a standard "party identification" question. First developed at the University of Michigan and used in all American National Election Studies (NES) since 1952, the core question asks people "Generally speaking, do you usually think of yourself as a Republican, a Democrat, an independent or what?"

Survey respondents' answers to this basic question -- and a follow-up that asks independents if they "lean" toward either party -- have been central to the study of voting behavior and understanding the electorate. The Washington Post asks this question in most polls.

The definition, meaning and durability of partisan identification is the subject of continued academic debate and is frequently at issue among political pollsters, but there is general agreement that partisan attachments are basically stable, although voting choices can vary over time.

While those who call themselves independents now may not have always done so, or continue to, they do represent a distinct group in American politics today, with demonstrable attitudinal and behavioral differences with those who embrace a "Democratic" or "Republican" label. In this poll, six in 10 independents said they have always thought of themselves that way.

And how many independents are there?

Through the 1950s and 1960s, about a quarter of adults identified themselves as independents in the NES. That percentage first hit 30 in 1968 and averaged about a third throughout the 1970s, 1980s and 1990s. This decade, the NES estimate of the number of independents has crept toward four in 10, with 39 percent calling themselves independents in the 2004 study.

National exit polls typically record fewer "independents" among actual voters (independents are less likely than partisans to vote). The first national exit poll, conducted in 1972 by CBS News and the New York Times, reported that 19 percent of Election Day voters were independents. In 1976, that number jumped to 34 percent and has hovered around a quarter of the electorate since 1980. In the midterm election this past November, 27 percent said they were independent, according to the exit poll conducted for the National Election Pool.

(Note that the reported exit poll percentage of independents is typically overstated by several points. The standard has been to include those who say "other" as part of a combined "independents" category. In 2006 for example, 23 percent indicated they were independents, four percent checked other.)

In this Post-Kaiser-Harvard survey, 29 percent of U.S. adults self-identified as independents. The average in Post-ABC News surveys over the past year is 34 percent.

The number of independents among the adult population and among voters varies for many reasons, including sampling error, method of data collection and changes in the partisan political landscape. Also, "independent" is a socially desirable label, one that even many partisans choose from time to time.

In this poll, about four in 10 Democrats and Republicans alike said they occasionally consider themselves to be independents. Even those who professed to being "strong" Democrats or Republicans sometimes wear the "independent" brand.

And most independents, when prompted in the second, follow-up poll question do accept partisan taglines. Here, two-thirds of self-identified independents said they lean toward one of the two major political parties. To some analysts this means that many independents are in fact "closet partisans," with fewer, around 10 percent, being "true" independents.

Many partisans have an independent streak and many independents walk and talk like Democrats or Republicans, so while it is useful and essential to understand the underpinnings of the group identities, it is also important to dissect them.

A Post-Kaiser-Harvard project nearly a decade ago segmented the partisan groups, now we investigate the crucial middle, the "independents."

© 2007 The Washington Post Company